bisecting fixing commit since 738d2902773e30939a982c8df7a7f94293659810 building syzkaller on 25a0186eba20ef6f4f657039ff02eff52a838b1c testing commit 738d2902773e30939a982c8df7a7f94293659810 with gcc (GCC) 8.1.0 kernel signature: c3573cb27f3c422040c8c9ed28085ef290961b3e1b06035f08df69b720158009 all runs: crashed: KASAN: slab-out-of-bounds Read in bacpy testing current HEAD 1b5044021070efa3259f3e9548dc35d1eb6aa844 testing commit 1b5044021070efa3259f3e9548dc35d1eb6aa844 with gcc (GCC) 8.1.0 kernel signature: caa3bb55f3767b48d26187397e870f3126cde50967e13c94c3ee3990b5051831 all runs: crashed: KASAN: slab-out-of-bounds Read in bacpy revisions tested: 2, total time: 19m29.977378591s (build: 12m6.877212674s, test: 6m37.918377476s) the crash still happens on HEAD commit msg: Merge tag 'dma-mapping-5.8-3' of git://git.infradead.org/users/hch/dma-mapping crash: KASAN: slab-out-of-bounds Read in bacpy ================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline] BUG: KASAN: slab-out-of-bounds in bacpy+0xe/0x10 include/net/bluetooth/bluetooth.h:274 Read of size 6 at addr ffff8880a6f04608 by task kworker/u5:1/7872 CPU: 1 PID: 7872 Comm: kworker/u5:1 Not tainted 5.8.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: hci0 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x134/0x187 lib/dump_stack.c:118 print_address_description.constprop.9.cold.11+0x9/0x41c mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold.12+0x20/0x37 mm/kasan/report.c:530 check_memory_region_inline mm/kasan/generic.c:186 [inline] check_memory_region+0x1cc/0x1f0 mm/kasan/generic.c:192 memcpy+0x23/0x60 mm/kasan/common.c:105 memcpy include/linux/string.h:406 [inline] bacpy+0xe/0x10 include/net/bluetooth/bluetooth.h:274 hci_extended_inquiry_result_evt net/bluetooth/hci_event.c:4394 [inline] hci_event_packet+0x334a/0x985e net/bluetooth/hci_event.c:6115 hci_rx_work+0x18e/0x950 net/bluetooth/hci_core.c:4705 process_one_work+0x893/0x1680 kernel/workqueue.c:2269 worker_thread+0x85/0xb60 kernel/workqueue.c:2415 kthread+0x383/0x460 kernel/kthread.c:291 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Allocated by task 7868: save_stack+0x21/0x50 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.18+0xc7/0xd0 mm/kasan/common.c:494 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:508 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node_track_caller+0x4d/0x70 mm/slab.c:3630 __kmalloc_reserve.isra.51+0x2c/0xc0 net/core/skbuff.c:142 __alloc_skb+0xd7/0x570 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:377 [inline] vhci_get_user drivers/bluetooth/hci_vhci.c:165 [inline] vhci_write+0xa8/0x3e0 drivers/bluetooth/hci_vhci.c:285 call_write_iter include/linux/fs.h:1907 [inline] new_sync_write+0x392/0x680 fs/read_write.c:484 __vfs_write+0x94/0x110 fs/read_write.c:497 vfs_write+0x190/0x530 fs/read_write.c:559 ksys_write+0x10b/0x220 fs/read_write.c:612 __do_sys_write fs/read_write.c:624 [inline] __se_sys_write fs/read_write.c:621 [inline] __x64_sys_write+0x6e/0xb0 fs/read_write.c:621 do_syscall_64+0x64/0xe0 arch/x86/entry/common.c:359 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 1: save_stack+0x21/0x50 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:455 kasan_slab_free+0xe/0x10 mm/kasan/common.c:464 __cache_free mm/slab.c:3426 [inline] kfree+0x108/0x2c0 mm/slab.c:3757 kernfs_fop_release+0x10a/0x170 fs/kernfs/file.c:782 __fput+0x2a7/0x790 fs/file_table.c:281 ____fput+0x9/0x10 fs/file_table.c:314 task_work_run+0xcc/0x160 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:216 [inline] __prepare_exit_to_usermode+0x215/0x220 arch/x86/entry/common.c:246 __syscall_return_slowpath+0x5a/0x280 arch/x86/entry/common.c:329 do_syscall_64+0x71/0xe0 arch/x86/entry/common.c:368 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880a6f04400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 8 bytes to the right of 512-byte region [ffff8880a6f04400, ffff8880a6f04600) The buggy address belongs to the page: page:ffffea00029bc100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a33088 ffffea00029b1c48 ffff8880aa400a80 raw: 0000000000000000 ffff8880a6f04000 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a6f04500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a6f04580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a6f04600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a6f04680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a6f04700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================